As a conventional method for calculating disparity information, there is a method using a two-dimensional phase only correlation (POC) (for example, see Patent Literature 1). As another conventional method for calculating disparity information, there is a method using a one-dimensional POC (for example, see Patent Literature 2). In addition, as a disparity calculating method using conventional segmentation, there is a method for dividing a reference image into small segments and estimating disparity values focusing on the boundary parts of the small segments (for example, see Patent Literature 3).